Improvement in steam-valves



H. E'. MARCHAND.

l Steam-Valve.: No.165'350,` PateptedJulyGMlSS.

UNrrE rrEs HENRY E. MARCHAND, `or PrrfrsRURe, PENNSYLVANIA.

iMPRoi/EMENT 1N STEAM-VALVES.

Spccification forming part of Letters Patent No. 165,350, dated July 6,1875; application tiled A -April 26, 1875.

To all whom it may concern Beit known that I, HENRY E. MARCHAND, ofPittsburg, in the county of Allegheny and State of Pennsylvania, 7haveinvented certain new and useful Improvements in Steam- Valves, of whichthe following is a specification This invention relates to a new andimproved steam-valve for that class of engines in which the valves areshifted by the direct action of steam operating alternately on each sideof the valve; and it consists, irst, in the combination, with saidreciprocating ported valve, of a cylinder constructed with four ports,two of which lead to each end of the same, serving in connection withthe ports of said valve and valve-box as induction and eduction portsfor the cylinder, in the manner hereinafter fully set forth; second, inthe combination of the reciliirocating ported valve, the valvebox andits four ports, and the cylinder provided with fourports, in the mannerhereinafter fully set forth.

In the drawings, Figure l represents a lon gitudinal sectional view ofmy improved valve and valve-box, showing a portion of the same of thesteam-cylinder to which it is attached. Fig. 2 represents a horizontalsection through the valve-box. Fig. 3 represents a transverse sectionthrough the valve-box and a portion of the steam-cylinder Fig. 4, alongitudinal vertical section through the cylinder and valve-box; andFig. 5, a transverse verticalV section through the upper part of thesteamcylinder.

The letter A indicates the cylindrical, semicylindrical, or polygonalvalve, having ports B, B, and C extending through the same. D representsthe valve-box, with a suitable bore or chamber extending through thesame, and

` provided with induction and eduction ports ing the induction-port ofthe'valvebox alternately with the ports H H in the valve-box and I I inthe cylinder, which serve as induc- .tion-ports for admitting steamalternately to each end of the cylinder. The port C extends throughthevalve and serves to connect the ports H H and I l with the induction .ordischarge port of the valve alternately at proper intervals, serving asan induction-port to the cylinder. K K represent two small ports in theupper wall of the valve-box, leading to each end of the interior of thesame from the induction-port, and serving to admit steam to both sidesot' the cylindrical valve,

for the purpose to be hereinafter explained. L represents a cylindricalchamber extending longitudinally through the upper part of the cylinderG, and provided with a shiftin g-valve, M. Said chamber'commuuicates atits ends with Vthe interior of the cylinder Gr, through ports N, witheach end of the valve-box l), through ports P P,`and with theexhaust-port of the valve-box by means of the port R. Said valve M isshifted as the steam is alternately admitted at each end of the cylinderby the action of the steam alternately opening and` closing the ports PP, and throwing the steamspaces in the valve-box at each end of thevalve A, alternately, into communication with the exhaust-port of thesaid valve-box. The valve-chest is provided with the usual induction andexhaust ports, indicated by the letters E and F, the exhaust-port havinga bridge, t, extending across the same, which closes the circumferentialexhaust-port in the main valve when feeding or exhausting through thelower ports. The letter S represents an auxiliary valve-box, formed onone side of the valve-box D, and communicating with the interior of thesame at each end by means ot' the ports T T, and at the center by aport, U. Said auxiliary valve-box is provided with a cylindrical valve,S', adapted to work therein in such manner as to alternately' establishcommunication between the ends of the valve-box and lthe port U. Thislast-mentioned auxiliary valve is intended to be used in connection withthe tappet-a-rm or eccentric of the engine to alternately establishcommunication with the ends of the valve-box and eduction-port of thesame, in place of the valve M, before Vfurther explanation.

described. To prevent the valve A from shifting around in/ the bore ofthe valve-box, a guide-pin, V, setting in a recess bored in the end ofthe valve A, is extended from either head of the valve-box D.

rIhe operation of my invention is as follows: The various parts of theengine being in the position shown in Fig. 1, upon admitting steam intothe eduction-port of the valve-box it takes the course through the portB into the port Las shown by the arrows, entering at one end of thecylinder. The port I', leading from the opposite end of' the cylinder,being connected with the exhaust-port of the valveboX by means of theport C, through the valve A, allows the steam behind the piston to driveit toward the opposite end ot' the cylinder. The valve M in the chamberL will be in position to close the port P, leading into the righthandend of the valve-box, and opening the port P at the left-hand end,establishing' communication between the latter end and the exhaust-portof the valve-box. The dii'erence in the pressure by this means createdkeeps the valve A in position until the piston reaches the opposite endofthe cylinder andshifts the Valve M, which immediately changes theports P P, opening communication between the opposite end ot' thevalve-box and the exhaustport, relieving the pressure on the right-handside of the valve and allowing the steam to shift it, so as to changethe induction and eduction-ports of the cylinder so as to admit thesteam on the left-hand side to make the return stroke of the piston.

The operation of the auxiliary valveV will be readily understood fromthe above without It will be evident from the above description that, asthe live steam is admitted at all times equally to both sides of thevalve, all

back-pressure of steam already used will be avoided, and a steam-cushionwill be formed at each end of the valve, as the ends of said valve-never close the ports. The valve, by reason of the live steam beingadmitted on both sides alike, will be perfectly balanced, and will actinstantaneously at each stroke ot' the piston of the engine, owing tothe large amount of steam. held at each end of the valvechest, whichserves as a reservoir, retaining the steam in readiness for action assoon as either end may be connected with the exhaust,l

and the equilibrium between the two sides destroyed.

The engine may be used by connecting the auxiliary-valve t0 the cam oreccentrierod, or in connection with the piston of the engine. In thenrst case, the auxiliary valve at the side ofthe valve-box is employed;in the latter, the reciprocating valve in the upper part of thecylinder.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

l. The combination of the reciprocating ported valve and the cylinder,constructed with four ports, I I and I I', two ot' which lead to eachend of said cylinder, serving in connection with the ports of the valveand valve-chest, as induction and eduction ports to said cylinder,substantially as described.

2. The combination 'of the reciprocating ported valve, the valve-box andits four cylinder-ports, and the cylinder provided with four ports,substantially as described.

In testimony that I claim the foregoing, I`

have hereunto set my hand.

HENRY E. MARCHAND. Witnesses JAMES L. Nonais, Jos. L. CooMBs.

